Many people are yet to receive the aid, which is piling up at Kathmandu airport following the 7.8-magnitude earthquake.

More than 7000 people have died and authorities have ruled out finding more survivors.

Nepal has banned large planes carrying relief supplies from landing at the international airport, after cracks appeared on the runway, reports the BBC.

Smaller craft are still permitted, but an official said unless action was taken Kathmandu Airport would be forced to close.

'Administrative issues'

On Saturday, Baroness Amos said she had reminded Prime Minister Sushil Koirala that Nepal had signed an agreement with the UN in 2007 for simpler and faster customs clearance for relief aid in a disaster.

"He has undertaken to ensure that happens, so I hope that from now we will see an improvement in those administrative issues," she told AFP.